Method of and apparatus for recovering oil



L. RANNEY June 23, 1931:

MsTHoD oF AND APPARATUS FOR REcovERING'oIL Filed April 8, i926 4 sheets-sheet 1 N MOOR AGU NENAS M2M/@0% y @351g o'mm y L. RAN N EY June 23, 1931.

i METHOD OF AND APPARATUS FOR RECOVERING OIL` Filed April 8, 1925 4 Sheets-Sheet 2 w. IU@

IIIII awww Jpne 23, 1931. L, RANNEY 1,811,560

METHOD OF AND APPARATUS FORREGOVERING OIL Fi1ea.Apri1 8. 192e` 4 sheets-sheet 5 LEO RAP/HEY vwantoz L. RANNEY lJune 23, 1931.

MTHOD OF AND APPARATUS FOR RECOVERING OIL Filed April s, 1926 4 Sheets-Sheet 4 m l NEL L50 HAN/YU fww I NNN guna/nto@ Patented June 23, 1931 UNITED STATES PATENT OFFICE LEO RANNEY, OF NEW YORK, N. Y., ASSIGNOR TO STANDARD OIL DEVELOPMENT COM- PANY, A CORPORATION 0F DELAWARE METHOD OF AND APPARATUS FOR RECOVERING OIT Application led April 8, 1926. Serial No. 100,531.

This invention relates to improvements in the recovery of oil from the earth by operations of the general type described and claimed in my United States Patents Nos.

1,634,235 and 1,634,236 granted June 28, 1927, of which the present application is a continuation in part. The invention will be fully understood from the followingdescription, taken in connection with the accomlo panying drawings, in which Fig. l is a diagrammatic vertical section showing an oil recovery system installed in accordance with my invention; l

Fig. 2 is an enlarged horizontal section .1.5 taken on line II-II, Fig. 1;

Fig. 3 is a longitudinal section through a. preferred form of connection for drilling into the oil sand;

Figs. 4 and 5 are diagrammatic horizontal sections illustrating methods of tapping extended areas of oil sand; and

Fig. 6 is a fragmentary vertical section illustrating an alternative to that shown in- Fiff. 1.

Ieferring rst to Figs. 1 and 2, a shaft 1 is sunk from the surface of the earth to a point adjacent an oil-bearing stratum 2. In the embodiment of the invention illustrated in these figures, the shaft is sunk through the sand 2 and into the lower cap-rock 3. A

suitable impervious wall 4, which may advantageously' be of concrete, is provided around the shaft where it traverses the oil sand, so as to prevent escape of gas, oil, or Water into the shaft. A mine gallery or tunnel 5 is driven from the foot of the shaft in a direction generally parallel to the plane of the oil-bearing stratum 2. Mine galleries extending in as many directions from the shaft as is desirable may be provided.

The gallery 5 traverses the low-er cap-rock 3 and is isolated thereby from the oil-bearing sand 2. An oil-collecting pipe 6 is ar,- ranged in the gallery and is provided with nipples 7 sealed in the lower cap-rock by 1mpervious material 7a. Such material may be tar, lead turnings, or the like. These nipples form mine wells and are preferably arranged at relatively closely spaced intervals throughout the gallery. Each nipple is provided with a valve, so that flow therethrough may be controlled as required. A pump 8 forwards the oil through lpipes 9 and 10 to a surface reservoir 11. The system so far described resembles that shown in my prior applications above referred to.

In accordance with the present invention, I excavaftene or more chambers 12 in the oil sand and drill or bore outwardly from these chambers into the sand. The chamber 12 is preferably walledand roofed with concrete 18. The present process is not recommended for use in fields where very high gas pressure prevails; in low pressure fields the excavation and concreting of the chamber 12 may be accomplished without undue diliiculty. The usual precautions should of course be taken against fire and the effect of. any gas upon the workmen.

A number of nipples 14; are fitted in per forations 15 formed for them in the wall of the chamber 12. The nipples are sealed in the wall by an impervious material 14a, or they may be set in place while the concrete is still plastic. They do not extend quite through the wall. It is desirable thaty all gas, oil and water be excluded from the workings, and after the chamber 12 has been completed no opportunity is given for access of such fluids from the sand to the chamber, gallery, or shaft except through the pipe system. A valve 14 is provided in the pipe connecting each nipple with the header 6, which discharges through pipe 6 into the main collecting pipe 6. The flow through these nipples may be individually and selectively controlled.

Precautions against inow of iiuids'while drilling are not essential in most of the fields best suited for workingA by my process. I prefer, nevertheless, to employ a drill fitting of the type shown in Fig. 3, because it is convenient and provides safeguards against any unexpected rush of gas or oil. The iittin comprises a nipple 16 having a gate valve 1' 95 installed at an intermediate portion. The rearward end of the nipple is screw-threaded or otherwise arranged to receive a cap 18, which is centrally perforated for passage of the hollow stem 19 of the drill bit 420. A 100 stuing box 21 containing packing 22 forms a part of the cap and seals the drill stem.

The cap also contains one or more lateral openings 23 screw-threaded or otherwise arranged for connection to the gas, oilor water-collecting pipes.

In operating this type of drill fitting a hole 24 is first drilled in the wall of the chamber 12, but not through into the sand, or the nip-v ple may be set in the concrete, as above mentioned. The gate valve is opened and the drill passed through it' into the forward portion of the nipple. 'Ihe cap 18 is then screwed in place and drilling may be commenced. Additional sections of drill stem are added as the drill penetrates the sand. Water for flushing the hole is passed into the hollow drill stem and is withdrawn with the cuttings from opening 2 3. When it is de- ;U sired to remove the drill, it is drawn back past the open gate valve 17, which is then closed. The cap may accordingly be safely taken oif and the drill removed, slnce fiow is stopped by the gate valve. The invention is 25 not limited to the use of this particular mechanism; other suitable'drill fittings will serve, frequently even though they j provide no .means for preventing escape of liuids when withdrawing the drill.

By drilling laterally from the chamber in the manner described, I am able to effect a very complete recovery of the oil from the sand. This is due not only to the extended area for drainage of oil into the collecting system, but also to the fact that the sand is tapped at the bottom. In this way the effect of gravity is utilized to the greatest extent.

The drilled holes may be run at any desired angle from the chamber. One method of 4o Working a tract or lease of forty acres, in the form of a square, is shown in Fig. 4 in which a tunnel or mine gallery 26 is excavated around the margin of the field. A number of collecting nipples 27 Yforming mine wells,

preferably 132 on each siderof the tract, are formed in the manner shown in Fig. 1. In addition, chambers 28, 29, 30 and 31 are excavated respectively at about the middle point of each side of the tract. These chambers are like those described in connection with Fig. 1.

From the chambers lateral holes 32 are drilled out into the sand in such manner as to 55, tap the greatest possible area. A radiating arrangement as shown is desirable. No dificulty is experienced in drilling to the desired distance in most sands. Usually the formation is not too hard to prevent passage of the drill, but is suciently strong to stand boring without caving. Two or three inch diameter holes may be drilled through the usual oil sand without any substantial danger of being stopped by-caving of the sand.

Drilling proceeds satisfactorily up to a lateral distance of 500 to 1000 feet or more from the chamber.

A well 33 is preferably sunk in the interior of the tract to serve as an inlet for air, as, or other fluid. When such Well is provi ed.

' the fluid is best forced through it into the oil sand. In this Way pressure is always exerted upon the oil and prevents the formation of low pressure areas that would retard flow. A single Well is usually suiicient for this purpose, but more may be provided if desirable.

Although not absolutely essential, the introduction of air or other gas is highly desirable. When `oil is withdrawn from the bottom area of the oil sand, as in accordance with the preferred form of the present invention, there is a tendency for the upper portion of the sand to retain by capillarity a considerable amount of oil. I have found that this oil may be expelled in large part, if the pressure prevailing in the sand is not allowed to fall substantially. For example, if the initial pressure in the sand is 30 lbs. per sq. in., I force in air through the central Well to maintain this pressure throughout the period of oil withdrawal. This causes the oil level to fall regularly, and the absorption and retention of oil in the upper areas is for the most part avoided.

If the operator has a tract adjacent to that enclosed by the gallery shown in Fig. 4, holes y 32 may be drilled outwardly to tap it. A single mine gallery and chamber may thus serve as a point of attack for a very large area. The arrangement of the chambers shown is merely illustrative. They may be placed at the corners of the tract or else- Where, as may be most convenient in view of the particular conditions to be met.

The corner arrangement of the chambers, illustrated in Fig. 5, is particularly suitable for Working a number of adjacent units. As shown, the chambers 33 34, 35, and 3G are formed at the corners of a forty-acre tract and the radiating holes 37 are formed in all directions into that tract and those adjoining it. A central pressure well 33 is provided, as described above. I may dispense with the mine wells formed from the gallery, when a large number of holes are drilled from the chambers. i

To facilitate the flow of oil I may 'use heat, suction, pressure or other agencies. Heating may be accomplished for example in the manner described in my above mentioned application Serial No. 14,448, closed or open steam pipes being inserted in the oil-collecting nipples. Ordinarily it is unnecessary to use Howfacilitating means in view of the very extended area of drainage openings formed by the lateral drilling into the sand from the chambers.

Fig. 6 illustrates an embodiment of the invention in which one or more chambers orpits 38, 38', are excavated through the upper cap-rock 39 into the oil-bearing sand 2. Each pit 38, 38', is referably provided with walls and ioor, o? concrete, or equivalent material. Suitable covers for the pits, or run-ways for the passage of the workmen,

will be provided. An oil-collecting pipe 40 and nipples 41 are provided. A pipe 42 for steam, compressed air, or other fluid, has branches`43 passing into the pit 38, and entering the nipples 41. If it is necessary to clean out the holes, a iuid under pressure is injected through pipes 43 and into the nipples through pipes 44. An easily removable joint 45 shouldr be provided between pipes 43 and 44, so that additional sections may be added to the latter. For the removal of sediment it is desirable to ext-end pipe 44 into the hole, Vuntil the obstructing mass is reached, and then inject steam, compressed air, or water, through the pipe. The sediment will A be swept out by the fluid between the pipe -ments in the above-described illustrative proand the wall of the hole. Suitable provision for receiving the sediment-carrying fluid will be made; for example, a tank with a pump line leading to the earth surface. Superheated steam is suitable for use when the eli'ect of heat in facilitating flow is desired.

If the sand isl underlain by water, the pits should not be excavated below the upper region of the sand. As the oil is withdrawn from this region the water will rise and force the oil ahead of it. It hydrostatic pressure of this nature is not available, it is usually best to sink the pit (as 38') as near as may be to the bottom of the sand. By drillvidually and selectively controlling simul taneous flow from a number of said openings.

2. Method of recovering oil from an oilbearing stratum, comprising forming a mine gallery adjacent and generally parallel to the stratum but spaced therefrom by a substantially impervious material, excavating a chamber from the mine gallery into the oilbearing stratum, sealing the chamber with respect to the stratum, drilling laterally from the chamber into the stratum in a. plane substantially parallel to the gallery, and collecting the oil from the drilled openings through a system sealed with respect to the chamber and, the mine gallery.

3. Method of recovering oil from the earth, comprising sinking a shaft to a point adjacent an oil-bearing sand, forming from the Shaft a mine gallery adjacent the sand but spaced therefrom by cap-rock, excavating in the sand a chamber communicating with the mine gallery, isolating the chamber from the sand by means of a wall of impervious ma- A terial, drillin laterally from said chamber a plurality o elongated openings into the sand in a plane substantially parallel to the gallery, and collecting the oil from the drilled openm s in a pipe system.

4. ethod according to claim 3, in which the gallery is run through the lower cap-rock and the chamber is made in theoverlying oilbearing sand.

LEO RANN EY.

ing at the bottom, gravity ilow is best utilized.

Air or other gas may be injected, as described above, to force the oil level downward. In

'some cases the same sand may be worked with pits of varying depth. Ordinarily, however, a sand will require tapping either at the top or at the bottom.

It will be understood that the thickness of cap-rock and oil-bearing strata varies greatly. The drawings do not purport to show any particular thickness. The tunnels outside the sand 'nay often'be f ormed in strata 'lying above or below a relatlvely thin cap-rock.

Various changes and alternatlve arrange- -elon ated o enings from said chamber and into the oilcaring stratum ina plane substantially parallel to the gallery, and indi- 

